The present invention relates to safety devices, and more particularly, to a combination drain opening screen and alternate drain path element for a sink or other liquid receptacle associated with a liquid reservoir. One form of the device is intended to insure that flammable solvents will not accumulate in significant quantities in an open or exposed receptacle as a result of accidental drain blockage.
Within the last few years, widespread use has been made of parts washers or cleaners which utilize a remote solvent reservoir, and a parts receiving sink or other receptacle into which a solvent conduit extends. A solvent pump is provided to pick the solvent up in the reservoir, force it through the conduit and onto an array of parts being washed in the sink. This provides a steady stream of solvent for washing action which may be carried out alone, or which may be aided by the use of a brush or other instrument manipulated by the operator. Parts washers of this type customarily have a cover unit for the receptacle or sink which is hingedly mounted and disposed atop the receptacle, where it is held in an open position by a fusible link. Accordingly, in the event of a solvent fire, the fusible link will melt, and the receptacle cover will fall under the force of gravity to cover the sink in an airtight manner, thus extinguishing the fire.
In parts washers of this type, one form of which is illustrated in U.S. Pat. No. 3,522,814, and in other types of parts washers, the sink or other receptacle is intended to be kept free of solvent unless the pump is operating.
Constructions of this type are made, and are recommended by safety authorities, because there is minimal exposure of solvent to the atmosphere. In other words, the liquid solvent is kept in the reservoir, and the reservoir is separated from the sink by a relatively small drain opening which is customarily partially closed off by a screen or so-called crumb cup. As long as the circulating pump is shut off, the sink is drained by gravity and solvent returns to a relatively safe place of storage.
Safety authorities and organizations are reluctant to endorse any construction wherein a large surface area of solvent is presented to the atmosphere, inasmuch as such large surface area presents a large evaporation potential and a correspondingly great fire hazard. Nevertheless, some workers using parts cleaners or washers of this type wish to soak articles to be cleaned in a solvent rather than taking the trouble to direct the stream of solvent onto the parts to insure proper cleaning. Accordingly, such parts washers users intentionally plug the receptacle or sink drain, as with a rag, for example, so that a certain volume of solvent will accumulate in the sink.
In other instances, a rag used by an operator may inadvertently plug the drain and thereby cause the solvent to accumulate in the sink. Thus, whether the sink drain is plugged accidentally or intentionally, and whether or not the operator is aware of the situation, a sink containing a significant volume of solvent constitutes a definite safety hazard to the worker, to other co-workers, and to the premises wherein the apparatus is being used.
Accordingly, in order to prevent personal injury or property damage arising from fire or explosion, there has been a need for a parts washer having means to insure that the solvent does not inadvertently collect any significant quantities in the parts receptacle portion of the parts washer unit. There has been a further need for designing a parts washer drain system which will tend to insure against both accidental and deliberate drain blockage.
There has been a further need for a relatively foolproof drain system which can be accomodated entirely within existing sinks or other receptacles without modification to the receptacle, and particularly, without the necessity of having parts or components lying outside the sink or other receptacle to achieve satisfactory performance from the standpoint of safety.
In view of the foregoing, it is an object of the present invention to provide an improved safety device for a solvent receptacle.
Another object is to provide a drain element for a receptacle which provides at least two drain paths, one of which is normal always in use and which communicates directly with the liquid sump or reservoir, and another of which extends away from the first element and provides an alternate drain flow path and a plurality of access openings to such path.
Another object is to provide a safety device comprising a combination strainer or small parts retainer and drain unit which includes portions cooperating with and engaging the receptacle so as to define a liquid flow path having plural access openings thereto.
Still another object is to provide a safety drain device and strainer combination which includes a direct fluid drain path and means defining a second drain path, with the second drain path extending both generally horizontally and generally vertically so as to provide plural regions of fluid pickup.
A still further object is to provide a combination strainer or small parts retainer and safety drain device which is contoured so as to resist even intentional attempted blockage thereof.
Still another object is to provide a safety drain device which includes plural openings communicating with an alternate drain path lying at various levels within the receptacle and at various distances from the periphery of the receptacle drain opening.
Another object is to provide a safety device of the above character which is of unitary construction and capable of simple and economical manufacture.
A still further object is to provide a safety drain device which will lie entirely within a safety receptacle so that a safety drain feature may be imparted to an existing receptacle without modifying the receptacle itself.
The foregoing and other objects of the invention, including certain inherent objects and advantages are achieved by providing a combination screen and drain element adapted for reception in a drain opening and including means with one portion thereof screening off a part of the existing drain path opening and having another portion defining both an alternate flow path and a plurality of access openings thereto, whereby fluid may flow from the receptacle to an associated drain or sump through one part of the screen unit, and wherein fluid may also flow by another path through the access opening and into the sump.
The exact manner in which these objects and advantages are carried into practice will become more clearly apparent when reference is made to the following detailed description of the preferred embodiments of the invention set forth by way of example, and shown in the accompanying drawings, wherein like reference numbers indicate corresponding parts throughout the several figures.